Header wrap? good or bad

dlampe · #1 (**permalink**) 03-03-2006, 05:37 PM

I have heard that header wrap will rust out your headers. Where does the moisture come from? It seems like if I keep the car dry and the pipes will be hot when the car is shut off, why would the wrap cause premature rust? If that is the case, how long could I run the header wrap with out any trouble?

Buzzmobile · #2 (**permalink**) 03-03-2006, 05:45 PM

Hey there Dean...Buzz in Tulsa here.

I tore my exhaust system down. totally hosed from the wrap. pitting, a couple cracks in the headers, I think you may have seen the one when you were down. Took the ceramic coating right off the portion of the sidepipes that were covered near the joint of the headers. The only reason I considered putting it back on was because the damage is already done and it is UGLY to look at

got the cracks fixed, but the system will never be pretty.

hope to see you soon..I suspect you will be down again in June...?

Buzz

Cobrabill · #3 (**permalink**) 03-03-2006, 05:47 PM

I had my headers wrapped that were ceramic coated first with no issues.However..............no header company will warrantee their headers if they've been wrapped.

mj_duell · #4 (**permalink**) 03-03-2006, 05:48 PM

I painted my headers with high-temp black (2 coats) then wrapped them two years ago. They have seen many heat cycles and extreme temps and are in perfect shape. I have heard bad things about the wrap, but I haven't had any issues. The only thing I did not like was the initial burn in, they smoked and smelled pretty bad for about a half hour. On the good side, there was a noticable reduction in heat under the hood. Just my .02

--Mike / Turn Ten Racing, Inc.

dlampe · #5 (**permalink**) 03-03-2006, 07:38 PM

I really like the look of wrapped headers. I might give it a try. I really want to get the car on the road and if I wait to get them coated, it will take another 2 weeks that I am not willing to wait. I think I will send the sidepipes off and get them coated while I wait for my headers to be finished.

Buzz, I will be at Clois's house next week! How many miles did you have on your car when you noticed the damage on your headers?

Buzzmobile · #6 (**permalink**) 03-03-2006, 07:45 PM

Great Dean, let's all get together. Nothing significant happening on this end. Finishing up the installation of the engine....because of a cracked header! (smiles) can't get those dang things out without pulling the motor. Had an oil leak I was chasing too, so no biggie!.

On the miles, not sure when it cracked. I just undid the wrap right around the time I met you and found the leak in the exhaust. I had taken the motor out and put it back in without undoing the wrap (stupid, I know). Finally, pulled it all off and there was the crack. But the main thing to come see is what it did to the sidepipes. You should come take a look. Looks like sand blast pits all through it with course blast media and took all the coating off of it. So to make a long story longer, the car is about a 94 model as best I can figure and it had 14K miles when I got it. I am pretty sure the crack was there when I bought it and I did not know.

Buzz

HI Cobra · #7 (**permalink**) 03-03-2006, 08:43 PM

I have had wraps on mine since it was built, about 5 yrs and 14k miles ago.
I pulled one side where the side pipes bolt to the headers to tighten the
flange bolts. The headers and side pipes are just painted with vht black paint. They looked like they did right before they were wraped - no harm done, and keeps the foot box much cooler. No problems here with the wraps.

tpiini · #8 (**permalink**) 03-03-2006, 08:58 PM

I wonder if it's not more dependent on the weather? My car lived within a hundred miles of Kansas City and started out with wrapped headers. At around 2 years & 5k miles, they were shot. Current headers are not wrapped & have about 6k on them. They look like new still. Perhaps Hawaii, Texas, Florida can take header wrap but us in the Midwest have our cars sitting all winter in high humidity. ??????????

Excaliber · #9 (**permalink**) 03-03-2006, 10:01 PM

I use it, good bad or ugly the bottom line is:

WAY cooler under the hood and in the footbox area. For me it's a 'must have'.

Buzzmobile · #10 (**permalink**) 03-03-2006, 10:24 PM

are you guys using the wrap that you seal with spray or just the wrap?

Excaliber · #11 (**permalink**) 03-03-2006, 10:30 PM

I use the spray after wrapping. Supposed to preserve it better? Some kind of silicone base stuff.

Buzzmobile · #12 (**permalink**) 03-03-2006, 10:32 PM

maybe that is the difference in success or failure. mine was just the wrap

HI Cobra · #13 (**permalink**) 03-03-2006, 11:16 PM

Mine is just the wrap. The humidity in Hawaii is about 60% most of the time. I make most of my trips to the North Shore and live on the north
east side of Oahu = plenty of salt air from the trades and no pitting or
rust on the wrapped pipes. Definitly not stainless either, just painted.
Like Ernie said, it does keep things cooler up front, but don't touch the
side pipes!

Michael C Henry · #14 (**permalink**) 03-04-2006, 08:45 PM

My car came with headers wrapped in fiberglass. It looked good .Underhood temps were reasonable . A week after driving the car home #7 left side blew out at first bend.Fiberglass everywhere. There was no point in trying to fix-patch-weld those headers .So many cracks.New headers are ceramic coated and it is working fine.So no to fiberglass wrap.

dlampe · #15 (**permalink**) 03-04-2006, 09:21 PM

Mike, how many miles on the car when you brought it home?

Loadco · #16 (**permalink**) 03-05-2006, 04:23 AM

Mine have been wrapped since new, 8 years and 11,000 miles ago. No problems and as everyone has pointed out under hood temps are lower. If you take your time and do it right I think it looks great.

dlampe · #17 (**permalink**) 03-05-2006, 06:28 AM

I would like to know why it works for some and not for others? Is it the VHT before the wrap or the sealer on the wrap or maybe pipe gauge? I don't know. I think I am going to try it. My FIA pipes run very close to my brake lines and I think I will benefit from the lower temperatures.

601HP · #18 (**permalink**) 03-05-2006, 06:58 AM

My pipes were Jet-Hot coated about 8 years ago with a coating that had a higher than normal temperature rating. I believe it is rated to 1900 degrees or something close to that. It is not a particularly attractive finish. Kind of sandy/grainy appearance, but I intended to wrap the pipes after the coating.

I did wrap the pipes after the coating was done (8 years ago). About 4 years ago I had the engine out and had to unwrap the pipes. There was absolutely no apparent damage to the coating. I re-wrapped the pipes after installing the engine. Last year I had to remove a small area of wrapping from several pipes. There was still no indication the wrap caused any problem. I attribute this to the coating. Those primary pipes have about 8,000 miles and 8 years on them.

David

CowtownCobra · #19 (**permalink**) 03-05-2006, 07:05 AM

I had both sides wrapped and last fall one tube cracked and a piece broke ending up with an unfixable hole. Had to have new headers made for that side. The ceramic coting had flaked off really bad. They looked bad enought that I left the other side wrapped.

The new side is nicely ceramic coted and I will NOT wrap them. If the other side cracks or breaks, I will do the same thing.

I'm not sure how this happened, they were wrapped for less than a year, the car is not driven in wet conditions. Bottom line, I don't recommend wrapping.

DJ

nevermind65 · #20 (**permalink**) 03-05-2006, 07:41 AM

I worked in an exhaust shop many years ago, and we ran into this all the time. The main reason they cracked was because of heat, not moisture. The wrap holds in the heat, which gives the header better flow. Unfortunately, this horrendous amount of heat causes the pipes to crack. There were other variables involved like the thickness of the pipe. A 2" diameter exhaust pipe could be had in 14, 16, 18, or even 20 gauge. Needless to say, the 20 gauge disintegrated pretty fast and would crack in no time at all.

Generally, on a carbed V8, it tended to be the tubes on the outer 4 corners that would crack the most. This was due to those cylinders running a bit lean compared to the inner 4.